US, Canada: Storm system to bring rounds of snow to portions of the US and Canada, Dec. 11-14

Event

A storm system will bring snow to portions of the Central Plains and Midwest regions of the US, as well as southeastern Canada, from Dec. 11-14. The affected areas include northern Kansas, southeastern Nebraska, central Iowa, northwestern Illinois, southern Wisconsin, northern Michigan, and northern Maine in the US, as well as southeastern Ontario, southern Quebec, and northern New Brunswick in Canada. Forecast models indicate snow will begin in Kansas and Nebraska in the afternoon of Dec. 11 and will spread northeastward toward Iowa, Wisconsin, and Illinois by the evening. On Dec. 12, the low will strengthen and the snow will become more intense as the precipitation extends to Michigan around midday and Ontario, Canada, in the afternoon. Snow, sleet, and freezing rain will arrive in Quebec by the evening of Dec. 12 and Maine, US, and New Brunswick, Canada by Dec. 13. The storm system will fully depart Canada on Dec. 14. Some uncertainty remains in the forecast track of the system and snow and ice amounts are subject to changes over the coming days.

Government Advisories
As of Dec. 10, the US National Weather Service (NWS) has issued winter storm watches for northern Michigan, while winter weather advisories are in effect for central Iowa, eastern Nebraska, and northwestern Missouri. Additionally, Environment Canada has issued special weather statements across portions of southern Ontario and southern Quebec due to snow, sleet, and freezing rain. Authorities will likely issue new alerts or update/rescind existing advisories as the winter storm transits the region over the coming days.

Hazardous Conditions
The latest forecast guidance indicates that widespread accumulations of 15-30 cm (6-12 inches) of snow are expected in the hardest-hit areas, including northern Michigan, interior southeastern Ontario, and interior Quebec. Accumulations of 10-15 cm (4-6 inches) are expected farther north and west in those regions where less precipitation falls and farther southeast where the snow may mix with freezing rain and sleet; this is most likely to occur in Ontario and Quebec. Accumulations of 2.5-10 cm (1-4 inches) are expected in Ontario north of the Greater Toronto Area, southeastern Quebec, Nebraska, Iowa, Illinois, and southern Wisconsin. Ice accretion of 0.6-1.2 cm (0.25-0.5 inches) are possible north of the Greater Toronto Area in Ontario and southeastern Quebec in Canada, as well as potentially northern Maine. In addition to the heavy snow, strong wind gusts could lead to periods of blowing and drifting snow. Sporadic power outages are likely throughout the affected area.

Transport
The inclement weather will likely cause widespread ground and air transport disruptions across the affected area through Dec. 12 in the Midwest US and Dec. 14 in Canada. Traffic and commercial trucking delays are possible along regional highways including the I-29, I-35, I-41, I-43, I-75, I-80, I-90, and I-94 corridors in the US, as well as the Trans-Canada Highway in Canada, Autoroute Jean-Lesage, Autoroute Felix-Leclerc, and Autoroute de l'Outaouais. Difficult and potentially dangerous driving conditions are also likely on secondary and rural roadways in the affected states as maintenance crews prioritize clearing major routes. Authorities could close stretches of highway if driving conditions become too hazardous. Gusty winds may threaten to topple high-profile vehicles throughout the affected area. Heavy wet snow and strong winds could bring down power lines and trees with foliage. Flight delays and cancellations are likely due to ground stops and deicing operations at regional airports including, but not limited to, those serving Des Moines (DSM), Milwaukee (MKE), Ottawa (YOW), and Quebec City (YQB).

Advice

Monitor local media for updated weather information. Verify road conditions before driving in areas where heavy snowfall is forecast. Allow extra time to reach destinations in these areas and carry an emergency kit and warm clothes if driving is necessary, especially on secondary or rural routes that could become impassable. Plan accordingly for delivery delays if routing shipments by truck through the affected area through at least Dec. 2. Confirm flights. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

National Weather Service
US Road Conditions
Meteorological Service of Canada